feat(bigquery): add internal listProjects API to core client

[keshavdandeva]

b/521443900

This PR introduces support for fetching a list of GCP projects via the BigQuery API. This functionality is being exposed primarily to support cross-project dataset resolution in the native BigQuery JDBC driver.

Changes included:

• Domain Model: Added Project domain model representing a BigQuery project (@BetaApi).
• Client Interface: Added listProjects(ProjectListOption... options) to the BigQuery client interface, marked as @InternalApi to preserve the public GA surface.
• SPI Layer: Added listProjects mapping to BigQueryRpc and implemented the underlying HTTP execution in HttpBigQueryRpc, including pagination and OpenTelemetry tracing support.
• Implementation: Implemented ProjectPageFetcher inside BigQueryImpl to seamlessly handle paginated project results.
• Testing: Added unit test coverage in BigQueryImplTest and HttpBigQueryRpcTest.

[gemini-code-assist]

Code Review

This pull request introduces the ability to list Google Cloud Projects accessible to the caller. It adds a new Project model class, a ProjectListOption class for pagination options, and the listProjects method to the BigQuery interface and its implementation BigQueryImpl. It also updates the underlying RPC layer (BigQueryRpc and HttpBigQueryRpc) to support the new API call with OpenTelemetry tracing, and includes corresponding unit tests. There are no review comments to address.

[lqiu96]

qq, what is the difference between id, numericId, and projectId?

From the link (https://docs.cloud.google.com/bigquery/docs/reference/rest/v2/projects/list), I see id and numericId, but not projectId

[keshavdandeva]

In the underlying REST API representation of a project (which maps to the client's ProjectList.Projects class):

• id: The top-level resource ID.
• numericId: The unique numeric project number (e.g., 123456789012).
• projectId: Extracted from the nested projectReference.projectId object (e.g., my-project-id), which is what other BigQuery APIs use to reference this project.

[lqiu96]

I don't think this should be too impactful otherwise, but you can have intellij autogenerate a value for this?

[keshavdandeva]

Done

[lqiu96]

hmm, I think this is an offical BigQuery api (https://docs.cloud.google.com/bigquery/docs/reference/rest/v2/projects/list) and we probably don't need to add InternalApi here.

[keshavdandeva]

Yeah, okay. Changed it to @BetaApi

[lqiu96]

qq, do you need retries for this?

Something similar to

google-cloud-java/java-bigquery/google-cloud-bigquery/src/main/java/com/google/cloud/bigquery/BigQueryImpl.java

Lines 648 to 665 in da1ccb1

	Tuple<String, Iterable<com.google.api.services.bigquery.model.Dataset>> result =
	BigQueryRetryHelper.runWithRetries(
	new Callable<
	Tuple<String, Iterable<com.google.api.services.bigquery.model.Dataset>>>() {
	@Override
	public Tuple<String, Iterable<com.google.api.services.bigquery.model.Dataset>>
	call() throws IOException {
	return serviceOptions
	.getBigQueryRpcV2()
	.listDatasetsSkipExceptionTranslation(projectId, optionsMap);
	}
	},
	serviceOptions.getRetrySettings(),
	serviceOptions.getResultRetryAlgorithm(),
	serviceOptions.getClock(),
	EMPTY_RETRY_CONFIG,
	serviceOptions.isOpenTelemetryTracingEnabled(),
	serviceOptions.getOpenTelemetryTracer());

[keshavdandeva]

Yeah, good catch. I'll add it

[lqiu96]

/gemini review

[gemini-code-assist]

Code Review

This pull request introduces support for listing Google BigQuery projects by adding the new Project model, ProjectListOption configuration, and the listProjects API method to the BigQuery service and its RPC implementation. Unit tests have also been added to verify the new functionality. The reviewer suggested improving null safety in the new Project class by annotating the nullable getter methods (getNumericId, getProjectId, and getFriendlyName) with @Nullable.